Riken



UNITED STATES PATENT FFICE.

, ROBERT DEMUTH, OF NEW YORK, N. Y., ASSIGNOR TO THE FARBENFAH RIKEN, VORMALS FR. BAYER & (30., OF SAME PLACE.

BROWN SULFUR DYE.

SPECIFICATION forming part of Letters Patent No. 603,755, dated May 10, 1898.

Application filed October 16, 1896. Serial No. 609,162. (Specimena) Patented in Italy January 13, 1896, XXXI, 40,624,

LXXIX, 407, and in France January 15,1896,N0.258,213.

To all whom it may concern.-

Be it known that 1, ROBERT DEMUTH, chemist, doctor of philosophy, a subject of the Emp'eror of Germany, (assignor to the FARBEN- FABRIKEN, VORMALS FR. BAYER & 00., of Elberfeld, Prussia,Germany,) temporarily residing in the city, county, and State of New York, have invented a new and useful Improvement in the Manufacture of Brown Coloring-Matters, (for which the aforesaid Farbenfabriken, vormals Fr. Bayer dz; 00., have already obtained Letters Patent in France, No. 253,213, dated January 15, 1896, and in Italy, Reg. Gen, Vol. XXXI, No. 40,624, Reg. Att, Vol. LXXIX, No. 407, dated January 13, 1896;) and I do hereby declare the following to be an exact and clear description of my invention.

My invention relates to the production of new brown coloring-matter dyeing cotton at ordinary temperature and resulting by the action of either sulfur and alkalies or alkaline sulfids or mixtures of sulfur and alkaline sulfids on cresol.

In the manufacture of the new dye I use the crude cresol or ortho cresol, meta cresol, para cresol, or any mixture Whatever thereof. Naturally the crude cresol will be mostly used for cheapness sake. The dyes thus obtained have nearly the same properties and are of considerable technical value, as they are capable of dyeing vegetable fiber or fabrics at ordinary temperature and do not require any handling of the goods to be dyed. They yield on Vegetable fiber or fabric in cold dyeingbaths, with or withoutan addition of alkaline sulfid, brown shades distinguished by their intensity and fastness.

, per cent. of NaOH.)

the desired temperature is reached. If after, say, four hours the melt has assumed the aforesaid temperature-via, 270 oentigrade the mass is kept at this temperature for about two hours. The resulting melt forms a solid mass, which, after cooling and pounding to pieces, can be used directly for dyeing purposes. The dyestuff thus obtained in the form of its sodium salt forms a black mass readily soluble in water, affording a greenish-black or bluish-black colored solution. The said solution dyes cotton a brown at ordinary temperature, and these shades are fast against washing. Moreover, it is not necessary to handle the goods to be dyed while being in the dyeing-bath, as the color strikes evenly on the fiber if the material is placed in the dyeing bath and kept therein for several hours.

On acidulating the aqueous solution of the dyestuff with mineral acids-for instance, muriatic acidthe dyestuff in the so-called free state is separated as a black precipitate,which when dried forms a brownish-black powder. This powder is insoluble in Water, sodium carbonate, ammonia, and alcohol. It

dissolves with difficulty in dilute soda-lye atv ordinary temperature,more easily in hot sodalye, producing a greenish-brown-colored liquid. It is dissolved with readiness by solutions of alkaline sulfids-forinstance, sodium sulfida greenish-brown-colored liquid being thus obtained. In concentrated sulfuric acid at 66 Baum it is insoluble or soluble with difficulty. Its solutions in alkaline sulfids possess the same dyeing properties as the aqueous solutions of the melt obtained as hereinbefore describedthat is to say, they dye cotton at ordinary temperature a fast brown.

Although in the above example I have de scribed crude cresol as the product to start from, (which will be mostly the case in practically manufacturing this d ye,) ortho cresol, meta cresol, para cresol, or any mixture whatever thereof can be used. The resulting products possess almost the same properties and also yield on cotton at ordinary temperature fast brown shades. The mode of working, the quantities of the materials used, and the temperature above referred to can vary within certain limits. The process proceeds in an analogous manner if potassa is used in place of soda or if alkaline sulfids or mixtures of sulfur and alkaline sulfids are allowed to act on cresol.

Having fully described my invention, what I claim, and desire to secure by Letters Patcut, is

1. The process of producinga new coloringmatter in the form of alkaline salts capable of dyeing vegetable fiber or fabrics at ordinary temperatures fast brown shades, which process consists in subjecting cresols and sulfur in strong alkaline liquid to temperatures above 200 centigrade, substantially as described.

2. As a new article of manufacture the brown coloring-matter producible from cresols and sulfur in alkaline solution at temperatures above 200 centigrade, being in the form of its alkaline salts a black mass easily soluble in water with a greenish-black or bluish-black color capable of dyeing cotton fabrics at ordinary temperatures fast brown shades, and having when precipitated with acids, the characteristics of a brownish-black powder insoluble in water, sodium carbonate, ammonia, and alcohol, soluble with difficulty in dilute soda-lye at ordinary temperature, more easily soluble in hot soda-lye with a greenish-brown color, insoluble or soluble with difliculty in concentrated sulfuric acid (66 Baum), easily soluble with a greenishbrown color in alkaline sulfids, thus afiording solutions which dye cotton at ordinary temperatures in fast brown shades substantially as described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

ROBERT DEMUTI-I.

Witnesses:

ERNEST HOPKINSON, W. LAIRD GOLDSBORQUGH. 

